数字式自动增益放大电路  

Design of Digital AGC Circuit

作　　者：王秀彦[1] 宋吟蔚[1] 宋国荣[1] 王庆锋[1] 

机构地区：[1]北京工业大学机电学院,北京100022

出　　处：《仪表技术与传感器》2008年第8期75-77,80,共4页Instrument Technique and Sensor

基　　金：国家"十一五"科技攻关项目(2006BAK02B01-09)

摘　　要：在数字信号采集系统中,A/D转换器对输入的模拟信号电压有一定的限制。为使输入信号不受这一限制,设计了一种数字式自动增益放大电路,该电路采用数字电位器取代放大器的反馈电阻,单片机根据放大器输出电压自动调整数字电位器的阻值来调节放大器增益,使输出电压始终维持在所设定的上下限电压之间。在实验室做了性能测试实验,结果表明:设计的自动增益放大电路性能稳定可靠,输出电压能够满足A/D转换器件的电压转换要求。In the system of signal acquisition, the A/D converter confined the input value of analog signal voltage. A digital AGC circuit using a digital potentiometer to replace the feedback resistance of the amplifier was designed. In order to get an appropriate gain, MCU adjusted the resistance of the digital potentiometer automatically according to the voltage value of amplifier＇s output. This system was tested faithfully in the laboratory. The experimental results show that the AGC circuit is reliable and meets the requirement of A/D converter.

关 键 词：自动增益控制 数字电位器 信号采集 

分 类 号：TP272[自动化与计算机技术—检测技术与自动化装置]